检索结果-南通市图书馆

Frontiers of Mathematics in China 2015年第2期10卷 351-365页

作者： Yong REN tingting hou R. SAKTHIVEL Department of Mathematics Anhui Normal University Wuhu 241000 China Department of Mathematics Sungkyunkwan University Suwon 440-746 Korea

We study a class of non-densely defined impulsive neutral stochastic functional differential equations driven by an independent cylindrical fractional Brownian motion （fBm） with Hurst parameter H ∈ （1/2, 1） in the Hilbert space. We prove the existence and uniqueness of the integral solution for this kind of equations with the coefficients satisfying some non-Lipschitz conditions. The results are obtained by using the method of successive approximation.

关键词： Stochastic functional differential equation non-densely defined operator cylindrical fractional Brownian motion (fBm) impulsive effect

Ecotoxicological effect of zinc oxide nanoparticles on soil microorganisms

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Environmental Science & Engineering 2015年第5期9卷 912-918页

作者： Zhaoyi SHEN Zhuo CHEN Zhen hou tingting LI Xiaoxia LU Laboratory for Earth Surface Processes (Ministry of Education) College of Urban and Environmental Sciences Peking University Beijing 100871 China

The widespread production and use of zinc oxide nanoparticles （ZnO-NPs） in recent years have posed potential threat to the ecosystem. This study aimed to investigate the ecotoxicological effect of ZnO-NPs on soil microorganisms using laboratory microcosm test. Respira- tion, ammonification, dehydrogenase （DH） activity, and fluorescent diacetate hydrolase （FDAH） activity were used as ecotoxicological parameters. The results showed that in the neutral soil treated with 1 mg ZnO-NPs per g soil （fresh, neutral）, ammonification was significantly inhibited during the study period of three months, but the inhibition rate decreased over increasing time. Inhibition in respira- tion was observed in the first month of the test. In various ZnO-NPs treatments （1 rag, 5 rag, and 10 mg ZnO-NPs per g soil）, DH activity and FDAH activity were inhibited during the study period of one month. For both enzyme activities, there were positive dose-response relationships between the concentration of ZnO-NPs and the inhibition rates, but the curves changed over time due to changes of ZnO-NPs toxicity. Soil type affected the toxicity of ZnO- NPs in soil. The toxicity was highest in the acid soil, followed by the neutral soil. The toxicity was relatively low in the alkaline soil. The toxicity was not accounted for by the Zn2＋ released from the ZnO-NPs. Direct interaction of ZnO-NPs with biologic targets might be one of the reasons. The adverse effect of ZnO-NPs on soil micro- organisms in neutral and acid soils is worthy of attention.

关键词： zinc oxide nanoparticles (ZnO-NPs) soilmicroorganisms respiration ammonification dehydrogen-ase (DH) activity fluorescent diacetate hydrolase (FDAH)activity

Simultaneously Enhanced Activity and Selectivity for C(sp^(3))-H Bond Oxidation Under Visible Light by Nitrogen Doping

在线全文

学校读者我要写书评

暂无评论

Transactions of Tianjin University 2021年第4期27卷 331-337页

作者： tingting hou Zhuyan Gao Jian Zhang Nengchao Luo Feng Wang School of Chemistry and Chemical Engineering South China University of TechnologyGuangzhou 510640China State Key Laboratory of Catalysis Dalian National Laboratory for Clean EnergyDalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China University of Chinese Academy of Sciences Beijing 100049China

Selective oxidation of saturated C(sp^(3))-H bonds in hydrocarbon to target chemicals under mild conditions remains a signifi-cant but challenging task because of the chemical inertness and high dissociation energy of C(sp^(3))-H *** photocatalysis can induce the generation of holes and oxidative radicals,off ering an alternative way toward selective oxidation of hydrocarbons under ambient ***,we constructed N-doped TiO_(2) nanotubes(N-TNTs)that exhibited remark-able activity and selectivity for toluene oxidation under visible light,delivering the conversion of toluene and selectivity of benzaldehyde of 32% and>99%,*** mechanistic studies demonstrated that the incorporation of nitrogen induced the generation of N-doping level above the O 2p valance band,directly contributing to the visible-light response of TiO_(2).Furthermore,hydroxyl radicals generated by photogenerated holes at the orbit of O 2p were found to be unselective for the oxidation of toluene,aff ording both benzaldehyde and benzoic *** incorporation of nitrogen was able to inhibit the generation of hydroxyl radicals,terminating the formation of benzoic acid.

关键词： Visible light c(sp^(3)) H oxidation N-doped TiO_(2) Selectivity Benzaldehyde

Regulation of superoxide flashes by transient and steady mitochondrial calcium elevations

在线全文

学校读者我要写书评

暂无评论

Science China(Life Sciences) 2014年第5期57卷 495-501页

作者： JIAN ChongShu hou tingting YIN RongKang CHENG HePing WANG XianHua State Key Laboratory of Biomembrane and Membrane Biotechnology Beijing Key Laboratory of Cardiometabolic Molecular MedicineInstitute of Molecular MedicinePeking-Tsinghua Center for Life SciencesPeking University

The mitochondria play essential roles in both intracellular calcium and reactive oxygen species *** a newly discovered universal and fundamental mitochondrial phenomenon,superoxide flashes reflect transient bursts of superoxide production in the matrix of single *** and how the superoxide flash activity is regulated by mitochondrial calcium remain largely *** we demonstrate that elevating mitochondrial calcium either by the calcium ionophore ionomycin or by increasing the bathing calcium in permeabilized HeLa cells increases superoxide flash incidence,and inhibition of the mitochondrial calcium uniporter activity abolishes the flash ***,the superoxide flash incidence is correlated to the steady-state mitochondrial calcium elevation with 1.7-fold increase per 1.0?F/F0 of Rhod-2 *** contrast,large mitochondrial calcium transients(e.g.,peak△F/F0~2.8,duration^2 min)in the absence of steady-state elevations failed to alter the flash *** results indicate that physiological levels of sustained,but not transient,mitochondrial calcium elevation acts as a potent regulator of superoxide flashes,but its mechanism of action likely involves a multi-step,slow-onset process.

关键词： superoxide flash calcium signaling reactive oxygen species (ROS) mitochondrion

Dynamics of triboelectric nanogenerators: A review

在线全文

学校读者我要写书评

暂无评论

International Journal of Mechanical System Dynamics 2022年第4期2卷 311-324页

作者： Guoqiang Xu Chuanyang Li Chaojie Chen Jingjing Fu tingting hou Yunlong Zi Department of Mechanical and Automation Engineering The Chinese University of Hong KongHong Kong SARChina Shenzhen Research Institute The Chinese University of Hong KongGuangdongShenzhenChina HKUST Shenzhen‐Hong Kong Collaborative Innovation Research Institute GuangdongShenzhenChina Thrust of Sustainable Energy and Environment The Hong Kong University of Science and Technology(Guangzhou)GuangdongGuangzhouChina Department of Mechanical and Aerospace Engineering The Hong Kong University of Science and TechnologyHong Kong SARChina

Triboelectric nanogenerators(TENGs)represent a promising next‐generation renewable energy *** have become increasingly popular for harvesting vibration energy in the environment due to their advantages of lightweight,broad range of material choices,low cost,and no ***,issues such as input force irregularity,working bandwidth,efficiency calculation,and dynamic modeling hinder the use of TENGs in industrial or practical *** this paper,the modeling process of the dynamical system of a TENG is reviewed from the perspective of energy *** addition,this paper reviews the main contributions made in recent years to achieve optimized output based on springs,magnetic forces,and pendulums,and introduces different ways to increase the bandwidth of ***,the main problems of TENGs in the process of harvesting vibration energy are *** review may serve as a practical reference for methods to convert irregular mechanical input sources into optimized output performance toward the commercialization of TENGs.

关键词： triboelectric nanogenerator vibration energy harvesting electromechanical coupling model broad bandwidth

Regulation of Active Oxygen Species by Grain Boundaries to Optimize Reaction Paths toward Aerobic Oxidations

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Energy & Environmental Materials 2021年第3期4卷 444-450页

作者： Zicheng Xie Jie Zhang Yu Xiao Yangcenzi Xie Wenkun Zhu Shuyi Yu tingting hou Shuquan Liang Liangbing Wang State Key Laboratory for Powder Metallurgy Key Laboratory of Electronic Packing and Advanced Functional Materials of Hunan ProvinceSchool of Materials Science and EngineeringCentral South UniversityChangsha 410083China State Key Laboratory of Environment-friendly Energy Materials Southwest University of Science and TechnologyMianyang 621010China

Aerobic oxidation by using molecular oxygen(O_(2))as the oxidant is highly attractive,in which activating O_(2)to reactive oxygen species(ROS)is a *** some progress has been achieved in regulating ROS by heterogeneous catalysts,the strategies to efficiently control ROS in aerobic oxidation are still urgently ***,grain boundaries(GBs)in metal oxides are discovered to be able to facilely regulate ***,MoO_(3)nanocrystals with high density of GBs(MoO_(3)-600)deliver a mass activity of 83 mmol g^(-1)h^(-1)in aerobic oxidation of benzyl alcohol,7 and 8 times as high as that of MoO_(3)nanoparticles without GBs and Pt/C,*** addition,the selectivity of benzoic acid is 100%during whole reaction process over MoO_(3)-*** studies reveal that the oxygen atoms at GBs in MoO_(3)-600 are highly active to form·OH radicals with the generation of oxygen vacancies,while the oxygen vacancies are replenished by O_(2).The reaction path directly contributes to the excellent catalytic performance.

关键词： molybdenum oxide aerobic oxidation grain boundary reactive oxygen species benzyl alcohol

Insights into effects of thermotolerant nitrifying and sulfur-oxidizing inoculants on nitrogen-sulfur co-metabolism in sewage sludge composting

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2024年第10期144卷 76-86页

作者： tingting hou Yujie Zhou Rongchun Du Jiali Liu Weiguang Li Shumei Zhang Muzi Li Junhong Chu Liqiang Meng Institute of Microbiology Heilongjiang Academy of SciencesHarbin 150010China Hebei University of Environmental Engineering Hebei Key Laboratory of Agroecological SafetyQinhuangdao 066102China School of Environment Harbin Institute of TechnologyHarbin 150090China

In this study,high temperature thermotolerant nitrifying bacteria(TNB)and high temperature thermotolerant sulfide oxidizing bacteria(TSOB)were obtained from compost samples and inoculated into sewage sludge(SS)*** effects of inoculation on physical and chemical parameters,ammonia and hydrogen sulfide release,nitrogen form and sulfur compound content change and physical-chemical properties during nitrogen and sulfur conversion were *** results showed that inoculation of TNB and TSOB increased the temperature,pH,OM degradation,C/N ratio and germination index(GI)of *** with the control treatment(CK),the addition of inoculants reduced the release of NH_(3) and H_(2)S,and transformed them into nitrogen and sulfur compounds,the hydrolysis of polymeric ferrous sulfate was promoted,resulting in relatively high content of sulfite and *** the same time,the physical and chemical properties of SS have a strong correlation with nitrogen and sulfur compounds.

关键词： Sewage sludge Composting Inoculation Thermotolerant nitrifying bacteria Thermotolerant sulfurized oxidizing bacteria

Au atoms doped in Ti_(3)C_(2)T_(x)MXene:Benefiting recovery of oxygen vacancies towards photocatalytic aerobic oxidation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2022年第4期15卷 2862-2869页

作者： Kaifu Yu Sanmei Wang Qi Li tingting hou Yue Xin Rong He Wenhua Zhang Shuquan Liang Liangbing Wang Wenkun Zhu State Key Laboratory of Environment-friendly Energy Materials National Co-innovation Center for Nuclear Waste Disposal and Environmental SafetySchool of National Defence Science&TechnologySouthwest University of Science and TechnologyMianyang 621010China State Key Laboratory for Powder Metallurgy Key Laboratory of Electronic Packing and Advanced Functional Materials of Hunan ProvinceSchool of Materials Science and EngineeringCentral South UniversityChangsha 410083China Hefei National Laboratory for Physical Sciences at the Microscale Synergetic Innovation Centre of Quantum Information&Quantum PhysicsCAS Key Laboratory of Materials for Energy ConversionUniversity of Science and Technology of ChinaHefei 230026China

Photocatalytic aerobic oxidation by using oxygen molecules(O_(2))as green and low-cost oxidants is of great attraction,where the introduction of irradiation has been proved as an efficient strategy to lower reaction temperature as well as promote catalytic ***,the oxygen vacancies(OVs)of catalyst are highly active sites to adsorb and activate O_(2)during photocatalytic aerobic ***,OVs are easily blocked by oxygen atoms from active oxygen species during the catalytic process,leading to the deactivation of ***,a promising catalyst toward photocatalytic aerobic oxidation was successfully developed by recovering the OVs through doping Au atoms into Ti_(3)C_(2)T_(x)MXene(Au/Ti_(3)C_(2)T_(x)).Impressively,Au/Ti_(3)C_(2)T_(x)exhibited remarkable activity under full-spectrum irradiation towards photooxidation of methyl phenyl sulfide(MPS)and methylene blue(MB),attaining a conversion of>90%at room ***,Au/Ti_(3)C_(2)T_(x)also manifested remarkable stability by maintaining>95%initial activity after 10 successive reaction *** mechanistic studies indicated that the OVs of Au/Ti_(3)C_(2)T_(x)served as the active centers to efficiently adsorb and activate O_(2).More importantly,the doped Au atoms of Au/Ti_(3)C_(2)T_(x)were conducive to the recovery of OVs during photocatalytic process from the results of theoretical and experimental *** recovered OVs of Au/Ti_(3)C_(2)T_(x)continuously and efficiently activated O_(2),directly contributing to the remarkable catalytic activity and stability.

关键词： oxygen vacancies doped Au atoms Ti_(3)C_(2)T_(x)MXene photocatalysis aerobic oxidation

Factors affecting directional migration of bone marrow mesenchymal stem cells to the injured spinal cord

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2014年第18期9卷 1688-1695页

作者： Peng Xia Su Pan Jieping Cheng Maoguang Yang Zhiping Qi tingting hou Xiaoyu Yang Department of Spine Surgery Orthopedics HospitalSecond HosptalJilin University Department of Endocrinology Second HosptalJilin University

Microtubule-associated protein 1B plays an important role in axon guidance and neuronal migration. In the present study, we sought to discover the mechanisms underlying microtu- bule-associated protein 1B mediation of axon guidance and neuronal migration. We exposed bone marrow mesenchymal stem cells to okadaic acid or N-acetyl-D-erythro-sphingosine （an inhibitor and stimulator, respectively, of protein phosphatase 2A） for 24 hours. The expression of the phosphorylated form of type I microtubule-associated protein 1B in the cells was greater after exposure to okadaic acid and lower after N-acetyl-D-erythro-sphingosine. We then injected the bone marrow mesenchymal stem cells through the ear vein into rabbit models of spinal cord contusion. The migration of bone marrow mesenchymal stem cells towards the injured spinal cord was poorer in cells exposed to okadaic acid- and N-acetyl-D-erythro-sphingosine than in non-treated bone marrow mesenchymal stem cells. Finally, we blocked phosphatidylinosi- tol 3-kinase （PI3K） and extracellular signal-regulated kinase 1/2 （ERK1/2） pathways in rabbit bone marrow mesenchymal stem cells using the inhibitors LY294002 and U0126, respectively. LY294002 resulted in an elevated expression of phosphorylated type I microtubule-associated protein 1B, whereas U0126 caused a reduction in expression. The present data indicate that PI3K and ERKI/2 in bone marrow mesenchymal stem cells modulate the phosphorylation of micro- tubule-associated protein 1B via a cross-signaling network, and affect the migratory efficiency of bone marrow mesenchymal stem cells towards injured spinal cord.

关键词： nerve regeneration bone marrow mesenchymal stem cells spinal cord injury microtubule-associated protein 1 B protein phosphatase 2A cell transplantation phosphorylation signal transduction NSFC grant neural regeneration

An Improved Method of the Energy Loss Calculation Considering the Volatility of Wind Power Generation

在线全文

学校读者我要写书评

暂无评论

Energy and Power Engineering 2017年第4期9卷 281-291页

作者： Bo Ruan tingting hou Yu Li Zhen Mei Jun Huang Research Institute of Economics and Technology Hubei Electric Power Company Limited Wuhan China State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science & Technology Wuhan China

The energy loss of the power grid is one of the key factors affecting the economic operation of power systems. How to calculate the electric energy consumption accurately will have a great influence on the planning, operation and management of the power grid. Currently there is a mountain of theoretical methods to calculate the line loss of the power system. However, these methods have some limitation, such as less considering the volatility of wind power resources. This paper presents an improved method to calculate the energy loss of wind power generation, considering the fluctuations of wind power generation. First, data are collected to obtain the curve of the typical daily expected output of wind farms for one month. Second, the curve of the typical daily expected output are corrected by the average electricity and the shape factor to obtain the curve of the typical daily equivalent output of wind farms for one month. Finally, the power flow is calculated by using typical daily equivalent output curve to describe the energy loss for one month. The results in the 110 kV main network show that the method is feasible.

关键词： The Energy Loss of the Power Grid Wind Power Generation Shape Factor the Curve of the Typical Daily Equivalent Output Power Flow Calculation